Electromagnetic relay



Dec. 29, 1953 K. 1.. JOHANSSON ELECTROMAGNETIC RELAY Filed Feb. 10, 1951 INVENTOR: K/Z/PZ lf/V/V/MT JO M/VSS O/V ATTORN EYS Eatentecl Dec. 29, 19 53 2,664,478 ELECTROMAGNETIC RELAY Karl Lennart Johansson, Bromma,

Sweden Application February 10, 1951, Serial No. 210,359

2 Claims. 1

This invention relates to electromagnetic relays and more particularly to such relays wherein the armature is substantially balanced.

An object of this invention is to procure a small relay which, contrary to the conventional relays, is appropriate to be used in mobile crafts such as automobiles, aeroplanes and rocket projectiles.

Thus a feature of the present invention is to produce a relay with very small dimensions.

Another feature is a relay consisting of simple parts thus simplifying the manufacture.

Another feature is a relay wherein the ore is provided with a pole-piece of magnetic material on each pole, which pieces are bent round the poles in L-shape that the legs of these pole-pieces parallel to the coil extended on the same side along the coil approach each other and form an air-gap.

Another feature is the armature by extending the leg along the coil of operated.

Another feature is the means for mounting the spring assemblies along the side of the coil. The sides of the leg farthest from the coil are extended sideways to carry the spring assemblies.

Another feature dimensions and a small mass.

Another feature is an armature which consists of a plate-shape piece of magnetic material movably mounted on the middle, thus forming two arms. The armature is mounted on the end of that leg of one of the pole-pieces which is farthest from the coil and movably suspended that one arm of the armature is placed between the coil and the leg on which it is mounted. This arm serves as a balance. The other arm of the armature is made to overbridge the air-gap between the two legs of pole-pieces and provided with one or two members for operating spring assemblies.

Another feature is the means for securing the armature to the pole-piece which consists of a pin made of ordinary round wire. The pin is bent in U-shape over at least a part of the armature and the ends of the pin are inserted in holes in the pole-piece and fixed.

Another feature is the method of utilizing the magnetic field that a high sensitivity of the relay is obtained.

Referring now to the drawing, Fig. 1 is a side is an armature with very small elevation of an electromagnetic relay embodying the feature of the invention.

Fig. 2 is a cross-section taken approximately on line bb of Fig. 1 showing the mounting means for the armature.

Fig. 3 is a cross-section taken approximately on line 0-0 of Fig. 1 showing the armature and the mounting of the spring assemblies.

With reference now to the drawing Figs. l3, the relay consists of a coil 1 on a core 2 having two L-shaped pole-pieces 4 and E of magnetic material attached to its poles, one on each end of the core. The legs 6 and l of the pole-pieces 4 and 5 respectively are extended on the same side along the coil towards each other and form an air-gap. The leg 7, which is farther from the coil than the leg 6 of the other pole-piece carries on the end the plate-shaped armature S of magnetic material. The armature is movably suspended on the middle at a line b-b, which is in substantially right angle to its longitudinal direction of the armature and between the ends of the pole-pieces. When the relay is magnetized, the forces exerted on the armature from the magnetic fields in the air-gaps El and it will cause the same moving direction on the armature. The armature is secured to the pole-piece by a pin I l of ordinary round wire bent over the armature in U-shape. The ends of this pin may be inserted in holes in the leg I and fixed on both sides at point l2. The armature is provided with slots [6 to diminish the mass and is carried out to be substantially balanced around the line 8 on accelerations in right angle to the longitudinal direction of the core. But, as the armature Millimeters Length of coil 27 Thickness of pole pieces 2.5 Width of pole pieces 17 Width of the armature 1? Thickness of armature 2 Spring assemblies 3 make contacts and 3 break contacts have shown that a maximum of sensitivity is obtained when the distance X in 1 same side along said coil that an air-gap is ob tained between said legs, one leg extended farther from the coil than the other, one ofsaid' legs being provided with extensions sideways beyond the coil carrying spring assemblies, an armature movably supported at the middle on the extremie ty of said leg farthest extended from the coil with one arm of said armature between this leg and t. e coil and the other arm on the outside of the other leg, said last arm provided with members for operating said spring assemblies, means for inovably holding of said armature on said leg.

2. An electromagnetic relay comprising a core with two poles, at least one coil-Winding on said core, coil carrying spring assemblies, a polepiece on each of said poles, said pole-pieces being bent around the ends of the coil in L-shape, the legs of said pole-pieces parallel to the coil being extended on the same side along said coil so that an airgap is obtained between said legs, one leg being extended farther from the coil than the other, one of said legs being provided with extensions sideways beyond the coil carrying spring assemblies, an armature movably supported on the middle at the extremity of said leg extended farther from the coil with one arm of said armature between this leg and the coil and the other arm on the outside of the other leg, said last arm provided with members for operating said spring assemblies, a suspending device for movably mounting said armature on said pole-piece, said suspending device comp-rising a U-shaped pin bent over'at least a part of said armature, the ends of said pin being fixed in said pole-piece.

KARL LENNART J OHANSSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 853,292 Birsfield May 14, 1%? 1,085,721 Berdon eb. 3, 191% 1,648,668 Westphal Nov. 8, 1927 2,455,049 Edwards et al Nov. 30, 19 .8 2,510,157 Towner et al. June 6, 1953 2,547,082 Towner et al. Apr. 3, 1951 FOREIGN PATENTS Number Country Date 185,100 Great Britain Sept. 6, 1923 

